1. Field of the Invention
This invention relates to a polyelectrolyte material, a method for manufacturing a polyelectrolyte material, a polyelectrolyte component, a fuel cell, and a method for manufacturing a fuel cell.
2. Background Art
With the advancement of electronics in recent years, electronic devices have become more downsized, more powerful, and more portable. In particular, downsizing and higher energy density for the cells used therein have become more required. Hence, middle-sized or downsized and lightweight fuel cells having high capacity has been emphasized.
In particular, Direct Methanol Fuel Cell (DMFC) in which methanol serves as the fuel is more suitable for downsizing than a fuel cell using hydrogen gas because there is no difficulty in handling hydrogen gas and a device and such for producing hydrogen by modifying a liquid fuel is not required. In the direct methanol fuel cell, methanol and water are supplied to fuel electrode side (anode electrode side), and methanol and water are reacted by a catalyst in the vicinity of a polyelectrolyte membrane to take out proton (H+) and electron (e−).
A widely used polyelectrolyte as a binder for such a polyelectrolyte membrane or a catalyst includes Nafion (registered trademark, DuPont Inc.). However, Nafion (registered trademark) has large thermal expansion or large expansion due to moisture and therefore has been in danger of causing “methanol crossover”, and has been also in danger of causing dissolution if continuing to contact a liquid fuel of high concentration (for example, methanol).
Accordingly, a polyelectrolyte material that can suppress methanol crossover and that is also chemically stable has been proposed (see, Japanese Patent Application Laid-Open JP-A 2006-261103(Kokai)).
However, such a polyelectrolyte material as disclosed in Japanese Patent Application Laid-Open JP-A 2006-261103(Kokai) requires introduction of a protective group for production thereof, and therefore, there has been danger that the production process gets complex and therefore the cost reduction cannot be achieved.